The full-size Chevrolet Suburban sport-utility vehicle has four doors, seats nine and tows a boat.

The full-size Chevy Tahoe SUV has four doors, seats six and tows a boat.

The full-size Ford sport-ute . . . Oops, there is no full-size Ford sport-ute.

Ford had the full-size Bronco, but it was a two-door and though it could tow a boat, it didn't handle that many people unless you stacked them like cord wood.

But Ford has finally decided to take on arch-rival Chevy for 1997 with a full-size, four-door sport-ute called Expedition that can tow a boat and haul a bunch of people. (Bronco has been dropped.)

Ford, however, had difficulty determining what big Chevy sport-ute it wanted to compete against--the nine-passenger Suburban or the six-passenger Tahoe--so it took on both with the 1997 Expedition that has Tahoe dimensions but Suburban seating.

Expedition is 15 inches shorter than Suburban, 6 inches longer than Tahoe and stands 5 inches shorter than Tahoe, so it's garageable. To comprehend the size, it's built on a 7.5-inch longer wheelbase and is 17 inches longer overall than the compact Ford Explorer.

The automaker chose to unveil Expedition here after someone in the Ford ranks thought the Alaskan wilderness an ideal backdrop for a vehicle named Expedition. Cute, but the media rang up more frequent-flier than road miles for this stunt.

Expedition basically is a Ford F-150 pickup from the front seat to the tip of the front bumper, including engine and transmission. With the F-150 heritage you get dual air bags and four-wheel anti-lock brakes as standard.

Expedition, which will be joined by a Mercury version called Navigator next year, comes in two- and four-wheel-drive XLT and Eddie Bauer versions.

Bauer is the top-of-the-line decor model and differs from the XLT in that it sports body-colored trim around the grille and tan trim along wheel wells and rocker panels.

A 4.6-liter, 215-horsepower, V-8 and a 5.4-liter, 230-h.p., V-8 are offered in each. The 5.4 is quieter and quicker. The 4.6, rated at 14 miles per gallon city/20 m.p.g. highway in 4x2, 14/18 in 4x4 (13/18 and 13/17 for the 5.4) is the choice for mileage, the 5.4 with 325 foot pounds of torque (290 for the 4.6) the choice for towing or climbing.

To compensate for the low mileage, 4x4s come with a much need 30-gallon tank versus 26 gallons for 4x2s.

There are also three suspension systems--base, rear-wheel air and four-wheel air--and 16-inch all-season or 17-inch all-terrain tires, available on 4x4 models only.

We tested Expedition in 4x2 and 4x4 with both engines, each suspension and XLT and Bauer versions.

The 4x2 is recommended for towing, the 4x4 for snow or off-road, the 5.4 for those who climb hills, go off-road or tow.

The base suspension is a bit harsh and allows an ample number of road blemishes to be felt throug h the wheel and seat. With rear-wheel air suspension the road smooths out; this system is recommended to keep the rear-end level when towing. Four-corner air provides optimum smoothness and softens the contact with the road without losing feel for the pavement. It keeps the vehicle level under any load or road condition for optimum ride, handling and braking.

Four-corner air suspension is advised for snow and off-roading because it automatically will raise the body up to 2 inches for added clearance. With four-corner air suspension, offered only on 4x4s, Expedition rides and handles very much like a luxury car. Expect the system--along with 4WD and the 5.4, V-8, to be standard on the Mercury Navigator.

Speed-sensitive power steering complements the suspension system. Steering is precise and you feel in control of the weight in the wheel without having to compensate for lean or sway.

The optional automatic four-wheel-drive system is like that o n the Explorer. Turn the dial on the dash to 4WD and when wheel slippage is detected, the system engages all the wheels. In worst-case scenarios, you can turn the dial to four-wheel low.

On an off-road course far more treacherous than a snow-caked Midwestern highway, automatic 4WD performed without problem.

Expedition is shorter than Tahoe, but stands tall enough for good down-the-road visibility, yet low enough so you don't feel top heavy and wobbly in corners and turns. Running boards, which come with lights that go on when the door is opened, are advised.

Expedition is a roomy, comfortable hauler offering two- or three-row seating. The split second seat folds to provide access to the rear. With three seats you can carry nine passengers like in a Suburban, but while a Suburban still has room to hold luggage or golf clubs or groceries behind the third seat, Expedition leaves just about enough room for a duffel bag and a set of irons--on top of each other.

The first and second rows of seats are comfortable and the second seat folds flat for sleeping on long trips. But the third is a tad cramped. It also sits a little higher than the second, so-called theater seating, and that robs headroom.

A final note on seats: Captain's chairs (standard in the Bauer) are the most comfortable but resist the optional lumbar support with their dumb inflatable bladder system that takes a sufficiently wide seat with ample side bolster support and converts it into a leather- or cloth-covered brick.

Kudos to Ford, though, for large outside mirrors that may cause some wind noise at speed with the windows down but provide a panoramic side and rear view, especially helpful when towing.

The option list is typical Ford--extensive and sure to be expensive. Noteworthy add-ons include large red arrows that flash in the sideview mirrors whenever using the turn indicators to warn drivers behind you are making a move, and rear-seat air conditioning.

There's a bevy of standard cup/juice-box holders and stowage compartments and two power plugs for add-on accessories.

Noteworthy, too, are items Expedition doesn't offer: passenger-side power seat, integrated child safety seat, spare tire (underneath) lock or a diesel engine.

One annoyance: You can't see the overdrive light on the steering-wheel stalk in the day.

Ford says most Expeditions will be ordered as XLT 4x4s with the 5.4-liter, V-8. Final prices haven't been set but the guesstimates are $30,000 for the base XLT, $35,000 for the Bauer, which adds a host of goodies such as power leather driver's seat, floor/overhead console, luggage rack, privacy glass, speed control, power rear quarter windows and tow hooks. Add $5,000 to either version to get it out the door fully equipped.

The obvious question is which is better, Expedition or Chevy Tahoe/Suburban. It really doesn't matter. What i s important is the competition in the full-size sport-utility market. As each rival tries to one-up the other, the consumer will benefit in terms of room, comfort, ride, handling, performance, fuel economy and safety.

But give Expedition the nod for now in terms of engines (the 5.4 is quieter and smoother than the 5.7-liter, 200-h.p., V-8 in Suburban and Tahoe) and four-corner air suspension. Give Suburban the nod for room and comfort without four-wheel air.

Ford sees full-size sport-ute sales rising to 270,000 in 1997 and 300,000 by 2000. Sales will total about 210,000 in 1996. Ford will build about 140,000 Expeditions annually to start, which may not sound like many. But keep in mind that Bronco sales never reached 100,000, and Expedition will be profitable considering about 50 percent of the vehicle was borrowed from the F-150 to dramatically cut costs.

Ford expects to lure customers away Suburban/Tahoe, especially those waiting mo nths for the high-demand/low-supply vehicles, as well as from mini-van and luxury-car owners looking for a more fashionable sport-ute.

>> 1997 Ford Eddie Bauer Expedition Wheelbase: 119 inches Length: 204.6 inches Engine: 5.4-liter, 230-h.p., V-8 Transmission: 4-speed automatic EPA mileage: 13 m.p.g. city/17 m.p.g. highway Base price: Not available. $35,000 estimated. Price as tested: Not available. But a long list of options should take you into $40,000 territory. Pluses: Built off F-150 truck platform. Gives Ford an entry in full-size sport-utility market and consumers another choice in that segment. ABS and dual air bags standard. Roomy, comfortable hauler that's garageable. Turn indicators in outside mirror a nice safety option. Dial-up 4WD without transfer case. Choice of versions: XLT or Bauer; engines: 4.6- or 5.4-liter V-8; and suspensions: off-road or on-road (wet or dry). Lights on running boards. Speed-sensitive steering. Minuses: In third-seat versions, cargo carrying capacity behind the seat is minimal. Response to low fuel economy is a larger 30-gallon tank. No child safety seats. No diesel option. Overdrive on/off on steering wheel stalk hard to see. No power passenger seat option. >>